Feature: Adds support to summarize perf counter errors for all failed instances

[LordHepipud]

Adds feature to Invoke-IcingaCheckPerfCounter to summarize an entire performance counter category, in case all instances of the check fail to prevent large outputs being written into the database

Invoke-IcingaCheckPerfCounter -PerfCounter '\processor(*)\% processor time';

[UNKNOWN] Performance Counter [UNKNOWN] \processor(*)\% processor time
\_ [UNKNOWN] \processor(*)\% processor time
   \_ [UNKNOWN] Internal Counter Error: Failed to fetch all instances and objects for this performance counter. First error message: Example error message

Fixes #348